Error message “unreported exception java.io.IOException; must be caught or declared to be thrown”

Error:

filecontent.java:15: unreported exception java.io.IOException; must be caught or declared to be thrown

showfile(); ^ filecontent.java:78: unreported exception java.io.IOException; must be caught or declared to be thrown

showfile(); ^

I have already thrown java.io.IOException, but still it shows these errors.

My code:

import java.awt.*;
import java.awt.event.*;
import java.io.*;

class filecontent extends Frame implements ActionListener
{
    TextField t[] = new TextField[4];
    TextArea ta[] = new TextArea[4];
    Button submit;
    Panel p1;
    filecontent()
    {
        setGUI();
        setRegister();
        showfile();
        setTitle("FileData");
        setVisible(true);
        setSize(300, 300);
        /*  addWindowListener(new WindowAdapter()
            { 
                public void windowClosing(WindowEvent we)
                { 
                    System.exit(0); 
                }
            }); 
        */

    }

    void setGUI()
    {
        p1 = new Panel();
        p1.setLayout(new GridLayout(5, 4, 10, 10));
        for(int i=0; i<4; i++)
        {